Haematoxylin

Part of speech: noun

Definitions

1. A powerful natural dye derived from the logwood tree, used primarily in histology to stain biological tissues for microscopic examination
2. A coloring agent extracted from certain plant sources, notably used in laboratories to visualize cellular structures under a microscope
3. An organic compound recognized for its ability to highlight and differentiate cellular components in biological samples during microscopy studies

Etymology: The name comes from the logwood tree, "Haematoxylum campechianum," whose heartwood is a deep red, the colour that gave it the Greek name "haima" (blood) plus "xylon" (wood). Compounds built from these two Greek roots name many plant genera, and this one describes the tree's colour. The compound itself is colourless. It is extracted from the wood and, once oxidised, forms hematein, which binds with metal salts called mordants to produce the blue-violet dyes that stain cell nuclei in microscope slides. The stain's colour therefore has little to do with the blood-red wood it came from.